Johann Gottfried Bernhard Bach (May 11, 1715 – May 27, 1739) was the fourth child to reach adulthood of Johann Sebastian Bach and Maria Barbara Bach. Born in Weimar, he attended the Thomasschule in Leipzig, his father providing for his musical formation. In contrast to his elder brothers Wilhelm Friedemann and Carl Philipp Emanuel he did not get the opportunity to study at the university after finishing school. Instead, he competed for a post as musician.
Johann Gottfried Bernhard first served as organist at the Marienkirche in Mühlhausen in 1735 and, after leaving the town charged with debts, managed with the support of his father to find a new engagement as organist at the Jakobikirche in Sangerhausen.
In 1738, he secretly abandoned a career in music in order to study Law in Jena. There he died prematurely at the age of twenty-four. Whether Gottfried Bernhard was also a composer as his brothers were is unknown.